• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.133-140
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• 2004

The histopathologieal effects of his(tri-n-butyltin)oxide (TBTO) on the flounder, Paralichthys otivaceus were examined by means of histological methods. The experimental fishes were exposed to 0.17, 0.36, 0.60, 3.20, 6.30, 12.50 ${\mu}g \;L^{-1}$TBTO concentrations for 42 days. Histopathological change of the fish exposed to TBTO is dependent on the exposure duration and concentration. In the lower concentrations early histological changes included activated mucous cells and chloride cells, capillary hyperemia and epithelial hyperplasia in the gill; hepatocyte activation, degeneration of bile duct and pancyeatic zymogen reduction in the hepatopancreas; and capillary hyperemia, appearance of eosinophilic cell and melano-macrophagocytes in the kidney. At the higher concentrations histological changes of dysfunctionality included epithelial lifting and deformation of the lamellae in the gill; pycnosis and cytoplasmic degeneration of hepatocyte; pycnosis of haemopoietic cell and deformation of renal tubules and glomerulus in the kidney. It is indicated that TBTO induced histopathological changes in the fish as other aquatic pollutants.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.569-576
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• 2007

receptor(MC4R) gene and carcass traits was examined in randomly selected commercial pigs. A porcine MC4R gene was genotyped for Asp298Asn(nt. 892G>A) by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). A total of three genotypes, A/A, A/G, and G/G, were found with 28.8, 22.8, and 48.4% frequencies, respectively. In the whole population, pigs containing 892A/- showed significantly higher marbling score than those of homozygotes G/G(P<0.05). Two homozygotes, A/A and G/G showed lower in meat color score but higher in water holding capacity than those of heterozygotes A/G(P<0.01). However, the carcass weight of the barrows containing wild type -/G was significantly higher(i.e. more than 2.5kg) than those of homozygotes A/A(P<0.05). The effects of each genotype on carcass traits in the gilts were similar to those of the whole population, but not in barrows, suggesting an unknown sex-related effect on carcass traits. This study suggested that the genotype MC4R A/- could improve the meat quality in the commercial pig production. However, since the genetic polymorphism of MC4R gene differentially affected the carcass traits in sex-related manner, therefore, both parameters, the sex and genotype, should be considered for marker-assisted selection in commercial pig production.

• Korean Journal of Environmental Biology
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• v.26 no.1
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• pp.30-35
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• 2008

In order to investigate whether or not CCD-986sk cell line can be affected by Korean Ecklonia stolonifera Okamura, we examined the MTT assay when we treated Korean Ecklonia stolonifera Okamura extract in CCD-986sk human fibroblast cell line. The sample were tested for cell proliferation activity by means of a modification of the MTT assay. Ecklonia stolonifera Okamura extract showed significantly strong cell proliferation activity at the range of from 6.25 mg $mL^{-1}$ to 1.56 mg $mL^{-1}$ compared with control group. And in order to search for inhibition agents of skin melanin formation, we tested for inhibition effect of melanin pigmentation of Korean Ecklonia stolonifera Okamura using Clone M-3 mouse melanocyte cell lines. when we treated the extracts of Ecklonia stolonifera Okamura to the mouse melanocyte cell lines, the sample showed a significantly little formation of melanin pigments compared with control group at the only range of 200 mg $mL^{-1}$. These results suggest that extract of Korean Ecklonia stolonifera Okamura may represents an excellent candidate for inhibition of melanin pigmentation and for protection of human skin aging at in vitro level.

• Journal of fish pathology
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• v.8 no.2
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• pp.119-134
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• 1995

To induce an overpopulated melanomacrophage centers(MMCs) within spleen and kidney in tilapias, two methods were applied through the intraperitoneal inoculation of V. anguillarum FKC with a repeated dose of saline(the 1st induction group), and of colloidal carbon (the 2nd induction group). In the 1st group, both number and size of MMCs were slightly increased in spleen and head kidney. However in the 2nd group the two hemopoietic tissues were nearly occupied with quite a large number of MMCs. Regardless of induction groups, many of MMCs were confined within the walls of blood vessels in the spleen. Especially in the 2nd group, the MMCs without fibrous capsules often had concentrically or eccentrically located, thin-walled lumens of vessels, which strongly suggests to be ellipsoids. In head kidney, nearly all MMCs were located within or just around the lymphocytic areas but the precise relationship to blood vessel wall was not obvious. Despite of such overpopulated MMCs, no histopathological degenerative findings in hemopoetic parenchymas of both organs were recognized. To evaluate the effect on defensive function, tilapias of the 2nd group were challenged with E. tarda. Susceptabilities to E. tarda were never increased but rather significantly decreased compared to control. Weekly antibody titres in sera were determined for all induction groups, in which the titres in the 1st and 2nd groups were 4 or 8 times higher than in the control, and then remained high until the 4th week. Also with the hemopoietic function, cellular compositions of peripheral blood were analyzed at weekly intervals but no significant changes resulted. From those results, it is suggested that overcrowding of MMCs would not lead to any morphological as well as functional deteriorations of spleen and head kidney but have an intimate association with enhancement of protective immune system in tilapias.

• Journal of Life Science
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• v.33 no.2
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• pp.169-175
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• 2023

As a protective defensive mechanism against ultraviolet (UV) light exposure in skin tissue, melanocytes produce the pigment melanin. Tyrosinase plays a key role in melanin production in melanocytes. However, the overproduction of melanin can lead to lesions, such as freckles and dark spots. Thus, it is clinically important to find a modulating molecule to control melanogenesis by regulating tyrosinase expression and/or activity. It is known that catechin, a plant flavonoid, can reduce melano- genesis through the downregulation of tyrosinase expression. Here, we tested whether catechin derivatives isolated from the stem bark of Ulmus parvifolia have an effect on melanin production by regulating tyrosinase in mouse melanoma cells and in vitro mushroom tyrosinase. The catechin derivatives used in this study included C5A, C7A, C7G, and C7X. Treatments using these catechin derivatives reduced melanin production in mouse melanoma B16F10 cells in which melanogenesis was stimulated by α-MSH. Notably, the anti-melanogenic effects of catechin derivatives were similar to those of kojic acid, a well-known anti-melanogenic molecule. Both C5A and C7A directly inhibited the activity of tyrosinase isolated from mushrooms in vitro. Furthermore, our in silico computational simulation showed that these two compounds were expected to bind to the active site of tyrosinase, which is similar to kojic acid. In addition, all four catechin derivatives reduced tyrosinase protein expression. In summary, our results showed that catechin derivatives can reduce melanogenesis by regulating tyrosinase activity or expression. Thus, this study suggests that catechin derivatives isolated from U. parvifolia can be novel modulators of melanin production.